I think it's valid not to answer that question for a number of reasons, though I don't think you were rude at all in asking it, OP.
I, for one, learned to evade that question after a couple of unfortunate experiences. I was on a train and a woman sat next to me who was very chatty. She asked me what I did for a living and I tried to evade by giving non-specific answers. We owned a small collection agency at the time, and after a couple of people having a VERY negative reaction to this, I decided to say simply "a financial company" instead. While not technically true, it wasn't completely false as we DID handle financial transactions. I just thought it was more PC than collection agency, because the industry has such a poor reputation (deservedly so in many instances. No argument there.)
Anyhow, she kept persisting wanting to know what business we had, (this was pre-ehell) and so I said "financial company." She assumed it was an investment firm of some kind and kept asking me for investment advice, and asking a lot of random questions such as "what's an annuity" and "how do you calculate compound interest". So, I learned after that not to disclose at. all. because now I just don't want to open that door. Thank goodness the business is gone and finished.
However, I notice that sometimes people start asking 20 questions and get really nosy. Not everyone, but sometimes. And with regard to my career, I just prefer not to talk about it, especially if it's uncomfortable, such as being unemployed. Not only is it embarrassing (to me) but even a vague answer elicits more questions. So I bean dip if it's something I just don't want to discuss. Nothing against that person - I just really, really don't want to talk about it, and I don't want to give any opportunity to discuss it. Since I'm not networking to actually get back into my old career and I'm working on certain projects at home (that have nothing to do with anyone else) I don't feel like sharing and opening up to criticism/unwelcome advice/commentary. (I'm not implying that the OP was in any way shape or form doing this; just explaining why *I* no longer like to answer questions that make me uncomfortable.)
Well, anyway, end thread hijack. But that's my personal reason for not answering anymore. Too many people got too nosy about it or decided to drop their two cents. I think a polite inquiry is fine, but when someone is evasive, it's polite to back off. (Again, not saying the OP did this at all.) But, too many people these days seem to think it's okay to play Watergate Congressional Hearing interrogator. He.
So, my general attitude is that if I'm not subpoenaed, I am gonna bean dip if I'm not comfortable answering for the above reasons. I really think a lot of people out there think it's polite to make small talk and then press the subject if they receive an evasive response...that they're showing an interest. But actually, I think when you get evasive answers (unless you are duly empowered to investigate
) the polite thing to do is to back off...which is what the OP did. Totally polite of you, OP. Wish more people are like you.